Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
A number of diagnostic methods have been developed to evaluate physiological conditions of a person by detecting and/or measuring one or more analytes in a person's blood or other bodily fluids or tissue. One or more target analytes could be any analytes that, when present in or absent from the blood, or present at a particular concentration or range of concentrations, may be indicative of a medical condition or health state of the person. These target analytes could include enzymes, reagents, hormones, proteins, cells, ions, e.g., sodium, potassium, calcium, or chloride, or molecules such creatine, urea, and carbohydrates, e.g., glucose. While many of the diagnostic methods that employ labeled agents are useful, they can be improved.
Much effort has been devoted into developing nanoparticles as vehicles for diagnosis, imaging as well as delivery of agents for treatment of disease. Nanoparticles have been conjugated to drugs, imaging agents or other substances that can be delivered to specific sites either by active targeting or by size-dependent passive targeting. However, one challenge associated with the use of nanoparticles is that individual nanoparticles may lack a set of desired chemical, physical or biological properties and it may be difficult to engineer multiple complex properties into a single particle type. Accordingly, there is a need for improved particles have a predetermined tailored set of properties that are useful in diagnostic, imaging and/or therapeutic methods to determine or monitor a medical condition or a person's state of health.